Neanderthals
(coming soon) History Why Neanderthals aren’t the brutish, primitive species we once thought - BBC Focus Magazine> Interbreeding https://en.wikipedia.org/wiki/Neanderthal#Interbreeding_with_modern_humans :"It is suggested that 20 percent of Neanderthal DNA survived in modern humans, notably expressed in the skin, hair, and diseases of modern people.155156source? Modern human genes involved in making keratin – the protein found in skin, hair, and nails – have specially high levels of Neanderthal DNA.156 For example, around 66% of East Asians contain the Neanderthal skin gene, while 70% of Europeans contain the Neanderthal gene which affects skin colour. POU2F3 is found in around 66 percent of East Asians, while the Neanderthal version of BNC2, which affects skin color, among other traits, is found in 70 percent of Europeans. Neanderthal are the variants in genes that affect the risk of several diseases, including lupus, biliary cirrhosis, Crohn's disease, and type 2 diabetes." :"Studies published in March 2016 suggest that modern humans bred with hominins, including Neanderthals, on multiple occasions.168 Another study in April 2016 found differences between modern human and Neanderthal Y chromosomes that, they postulated, could cause female Homo sapiens sapiens to miscarry male babies that had Neanderthal fathers.169 This could explain why no modern man had to date been found with a Neanderthal Y chromosome.170 Melanesians and Australoid populations show evidence of only one interbreeding event, possibly about 100,000 years ago, occurring in the Middle East, Europeans show a second event, which may also be of Middle Eastern origin, occurring possibly 50,000 years ago, while East Asians show an additional third interbreeding event possibly 30,000 years ago occurring in Siberia. Evidence that Neanderthal genomic material is often found amongst genes of the immune system suggests that some of the interbreeding may have secured resistance to diseases that Neanderthal populations had bred resistance to.168" Extinction https://en.wikipedia.org/wiki/Neanderthal#Extinction :"Possible scenarios for the extinction of the Neanderthals are: :* Neanderthals were a separate species from modern humans, and became extinct (because of climate change or interaction with modern humans) and were replaced by modern humans moving into their habitat between 45,000 and 40,000 years ago.175 Jared Diamond has suggested a scenario of violent conflict and displacement.176 :* Neanderthals were a contemporary subspecies that bred with modern humans and disappeared through absorption (interbreeding theory). :* Volcanic catastrophe: see Campanian Ignimbrite Eruption" Genetics Viruses |Nature:/Genomics2018/Neanderthal liaisons bestowed virus-fighting genes on humans> :"Interspecies mating helps to protect Homo sapiens against viruses." :"Modern Asian and European human genomes are made up of 2–3% Neanderthal DNA, a relic of prehistoric mating between the two hominin groups. To learn more about the genetic impact of this exchange, David Enard from the University of Arizona in Tucson and Dmitri Petrov at Stanford University in California looked for Neanderthal DNA in regions of the modern human genome that code for proteins that interact with viruses. :The researchers found that Neanderthal DNA was more common in these virus-fighting areas than elsewhere in the modern human genome. These sections of DNA also tended to be longer, and were found more frequently in modern humans, than other Neanderthal segments." Autism UW prof delves into why we got genes linked to autism, but Neanderthals didn’t - GeekWire "One of the biggest genetic differences between humans and other members of the primate family tree, including Neanderthals, predisposes people to a type of autism. The stretch of DNA appears to be an important piece of the human genome, but why? University of Washington genome scientist Evan Eichler and his colleagues on an international research team focus on that question in a study published today by the journal Nature. The key genetic structure consists of 95,000 molecular base pairs in a region on chromosome 16 that’s known as 16p11.2. The structure includes 28 genes, flanked by blocks of DNA with duplicated sequences of genetic code known as copy-number variants. Eichler’s team compared the genomes of modern humans with the genetic code for chimps, gorillas and orangutans, as well as the code for Neanderthals and another strain of extinct pre-humans known as Denisovans. Humans were the only ones to have the structure in the 16p11.2 region. The researchers’ analysis indicates that the structure appeared in our ancestors’ genome relatively suddenly, about 280,000 years ago. That time frame is about 80,000 years before anatomically modern humans – that is, Homo sapiens – show up in the fossil record. “Most duplications in our genome are millions of years old, and the speed at which this structure transformed our genome is unprecedented,” Eichler said in a news release." "Researchers have previously taken note of the structure in 16p11.2 because a mutation that results in the deletion of genetic code is correlated with about 1 percent of autism cases. But the structure also contains a beneficial gene called BOLA2. That gene seems to plays a part in helping cells capture iron more efficiently and making iron available to proteins that need it. The iron-building benefit is most pronounced early in cell development. “This ability to help humans to acquire and use this essential element early in life might confer a significant enough benefit to outweigh the risk of having some offspring with autism,” Eichler said." Emergence of a Homo sapiens-specific gene family and chromosome 16p11.2 CNV susceptibility - Nature "Genetic differences that specify unique aspects of human evolution have typically been identified by comparative analyses between the genomes of humans and closely related primates1, including more recently the genomes of archaic hominins2,3. Not all regions of the genome, however, are equally amenable to such study. Recurrent copy number variation (CNV) at chromosome 16p11.2 accounts for approximately 1% of cases of autism4,5 and is mediated by a complex set of segmental duplications, many of which arose recently during human evolution. ... All humans examined carried one or more copies of the duplication, which nearly fixed early in the human lineage—a pattern unlikely to have arisen so rapidly in the absence of selection (P'' < 0.0097). We show that the duplication of ''BOLA2 led to a novel, human-specific in-frame fusion transcript and that BOLA2 copy number correlates with both RNA expression (r'' = 0.36) and protein level (''r = 0.65), with the greatest expression difference between human and chimpanzee in experimentally derived stem cells. Analyses of 152 patients carrying a chromosome 16p11.2 rearrangement show that more than 96% of breakpoints occur within the H. sapiens-specific duplication. In summary, the duplicative transposition of BOLA2 at the root of the H. sapiens lineage about 282 ka simultaneously increased copy number of a gene associated with iron homeostasis and predisposed our species to recurrent rearrangements associated with disease." 2018 Journal The same gene that is associated with 1% of autism cases is also a gene that gives increased retention of iron in cells... could cell permeability to metallic nanoparticles be correlated to autism? Meaning that autistic people are more sensitive to nanoparticles of toxic metals? Ethno-linguistic Trends Sub-Saharan Indigeneous Africans http://www.bbc.com/news/science-environment-34479905 ""Once again, like in the case of Europe where we see dramatic genomic turnover, the spread of agriculture has had a huge impact even in a continent where large groups continued to be hunter gatherers. "And it is also interesting to discover now that even sub-Saharan Africans have a bit (0.3-0.7%) of Neanderthal ancestry.""http://www.bbc.com/news/science-environment-34479905 North Africans, Semites and Caucasians "An ancient African genome has been sequenced for the first time. Researchers extracted DNA from a 4,500-year-old skull that was discovered in the highlands of Ethiopia. A comparison with genetic material from today's Africans reveals how our ancient ancestors mixed and moved around the continents. The findings, published in the journal Science, suggests that about 3,000 years ago there was a huge wave of migration from Eurasia into Africa. This has left a genetic legacy, and the scientists believe up to 25% of the DNA of modern Africans can be traced back to this event. "Every single population for which we have data in Africa has a sizeable component of Eurasian ancestry," said Dr Andrea Manica, from the University of Cambridge, who carried out the research." Eurasians (coming soon) "Genetic studies have shown that after the great migration out of Africa, which happened about 60,000 years ago, some people later returned to the continent. But this study shows that about 3,000 years ago there was a much larger migration than had been thought." "The Eurasians' return also introduced some extra genetic material to Africa. The genes their ancestors had picked up from interbreeding with Neanderthals were then passed to Africans, and can still be seen today." References Category:Evolutionary Biology Category:Life Category:Consciousness Category:Biology Category:Chronobiology